Several forms of surgery and medical treatment utilize specialized surgical instruments that require a supply of power or material to operate. For example, such specialized surgical instruments include an electrosurgical instrument, cryosurgical instrument or waterjet instrument.
Electrosurgery is the application of a high-frequency electric current to biological tissue as a means to cut, coagulate, desiccate, or fulgurate tissue. Its benefits include the ability to make precise cuts with limited blood loss. In electrosurgical procedures, the tissue is heated by an electric current manipulated using an electrosurgical instrument, which must be supplied with electrical power. Electrosurgical devices may be used for the cauterization of tissue in some applications or, more often, in dermatological, gynecological, cardiac, plastic, ocular, spine, ENT, maxillofacial, orthopedic, urological, neuro- and general surgical procedures, as well as certain dental procedures. Electrosurgery is performed using an electrosurgical generator (also referred to as power supply or waveform generator) and a handpiece, i.e., the electrosugical instrument, including one or several electrodes, sometimes referred to as an RF Knife.
Cryosugery is a technique employing the use of low temperatures to destroy cells and abnormal or diseased tissue. The low temperatures are applied using a cryosurgical instrument, which must be supplied with cryogenic material, e.g., liquid nitrogen. Such cell or tissue death is usually by plasma membrane and protein disruption via physical and osmotic damage when ice crystals form within the cytoplasm of the cells. Warts, moles, skin tags, solar keratoses, Morton's neuroma and small skin cancers, for example, are candidates for cryosurgical treatment. Several internal disorders are also treated with cryosurgery, including, for example, liver cancer, prostate cancer, lung cancer, oral cancers, cervical disorders and, commonly in the past, hemorrhoids. Soft tissue conditions such as plantar fasciitis and fibroma can be treated with cryosurgery. Generally, damaged or diseased tissues that can be reached by the cryoprobes used as surgical instruments during an operation are treatable.
Waterjet surgery is a minimally traumatic surgical method for dissection of tissues. For example, waterjet surgical techniques can be used in various parenchymal organs and allow highly precise parenchymal dissection while preserving blood vessels, resulting in reduced intraoperative blood loss. In such surgery, a waterjet surgical instrument is used in the process and must be supplied with water.
Supply devices used for operating a surgical instrument, such as, the electrosurgical, cryosurgical or waterjet surgical instruments discussed above have included a control unit for controlling the instrument, as well as a memory unit for storing configuration data describing a finite-state machine (also referred to as a finite-state automaton), i.e., a state automaton featuring a plurality of states. Such a control unit is configured such that it reads in the configuration data, translates the finite automaton into a control program and controls at least one instrument consistent with the control program. A surgical instrument that is connected to a surgical apparatus can thus be programmed in a simple manner, and a verification of the accuracy of programming is ensured rapidly and efficiently with the use of a state automaton.
Considering known supply devices, a framework program or a framework within such a supply device is provided, which allows the control program for the instrument to be read in and translated in the form of a state automaton. The term “state automaton” is used herein as a term synonymous with a finite-state automaton or a finite-state machine, i.e., generally representing a model of a behavior, consisting of states, state transitions and actions. Usually, the above-addressed framework program need not be modified to further develop the functionality of the supply device. The actual control of the instruments takes place with the use of the state automaton that is described by configuration data. It is very easy to validate if a state automaton is correct. Preferably, deterministic automatons are used, so that it is easy to verify whether the automaton functions correctly. Due to the use of state automatons, it is possible to minimize the amount of work in the process of developing new control and regulating algorithms, whereby the safety of the patient and of the personnel operating the supply device is ensured at all times.
Considering supply devices of the known type, there is the problem that, while the control program is running, for example, for changing the intensity of a tissue effect and, in particular, for changing the voltage, a current or an output, it is necessary—in certain situations—that a change of the default values or the adjusted values must be made at several points in the implementation of the state automaton. When conventional supply devices are used, the user must perform manual adjustments on adjustment devices such as potentiometers or the like.
However, with the use of a state automaton, such a manual adjustment of parameters is not possible due to the complexity of the system. Consequently, while the state automaton is running, a user cannot perform any manual change, for example, of the output voltage or output power or the like, by actuating an adjustment device of the surgical apparatus. Further, generating a dedicated control table for the state automaton for any possible adjustment value of the adjustment device(s) would consume an enormous amount of time and would greatly reduce the advantages of clarity and the simple maintenance of the control feature by means of a state automaton.
Another disadvantage of the known supply device is that tissue parameters and/or RF measured values affecting the state transitions of the automaton define only the implementation of the state automaton and not the intensity of individual control values. In doing so, it would be desirable that the tissue parameters and/or the RF measured values not only affect the implementation of the state automaton but, in addition, can effect a change of the control parameters such as, for example, voltage, time, current, output, etc.
Therefore, there is a need for a supply device for a surgical apparatus for operating at least one surgical instrument that allows a manual influence by the user over the control values of the state automaton while the state automaton is running and also allows a change of the control values based on tissue parameters and/or RF measured values or the like, where the values are used as conditions for the state transitions between two states of the state automaton.